People have laid flowers and scrawled messages of support on a footpath in the centre Brussels, in the wake of the deadly bombings.
In a sign of solidarity people chalked messages in French, English and Arabic, while others lit candles.
Around the world landmarks have been lit up in the colours of the Belgium flag, including the Eiffel Tower and Trevi Fountain.
Australian Prime Minister Malcolm Turnbull has condemned the attacks which have claimed the lives of at least 34 people and injured more than 100.
“We are absolutely shoulder to shoulder with Belgium, and the people of Belgium in this fight against terrorism,” he said.
There have been no reports of Australian casualties, but Mr Turnbull says it’s still early days.
Australians have been advised to avoid all unnecessary travel to the city.
